White poplar

Other Names

AbeelAbeleAk kavakÁlamo blancoAubeauAubelBai Yang ZhiBěły topołChopo blancoChoupo-brancoEun-baek-yangEuropean White PoplarFarfarusFolharançoGatticeGemma populiGin-doroHakuyoHopeapoppeliHour abyadLeuceLeukaObelOculi populiPeuplier blancPioppo biancoPopolo alboPoppelbaumPopulus albaPopulus alba L.Populus alba var. bolleanaPopulus alba var. canescensPopulus alba var. denudataPopulus alba var. microphyllaPopulus alba var. niveaPopulus alba var. pyramidalisPopulus bolleanaPopulus caspicaPopulus denudataSafedaSilber-PappelSilberpappelSilver PoplarSilver-Leaved PoplarSilverleaf PoplarSølv-PoppelTopol belyyUrajiro-hako-yanagiWeißpappelWeisz AlberbaumWitpopulierWitte abeelXin bai yangYin bai yangYpréau银白杨

Synopsis

White Poplar (Populus alba L.): A Comprehensive Reference

1. Identity and Botanical Description

Nomenclature and Taxonomy

White poplar bears the scientific name Populus alba L. and belongs to the family Salicaceae. Its full taxonomic classification places it in the Kingdom Plantae, Order Malpighiales, Family Salicaceae, Genus Populus, Section Populus. The species epithet alba (Latin: white) refers to the distinctive whitish undersides of its leaves and the pale bark of younger branches. Common English names include white poplar, silver poplar, and abele. Additional names from various languages and traditions include Yin bai yang (Chinese), Peuplier blanc (French), Silberpappel / Weißpappel (German), Safeda (South Asian), Pioppo bianco (Italian), Álamo blanco / Chopo blanco (Spanish), and Ak kavak (Turkish).

Morphological Description

Populus alba is a tree growing up to 30–35 metres in height. The crown is wide and tent-shaped, starting low from the ground. The bark of the trunk and large branches is gray-green and smooth, becoming dark gray or black with age. Leaves are ovate-round or ovate-triangular, with the upper surface dark green and shiny and the lower surface silvery with white pubescence. White poplar has a powerful root system extending beyond the projection of the crown, consisting of both deep and above-ground roots.

The species is native to Europe and Central Asia and has become naturalized in various parts of the world, including North America. It is known for its aggressive growth habit, spreading rapidly through root suckers.

Plant Parts Used Medicinally

The primary plant part used as a dietary supplement or herbal medicine is the stem bark, harvested from branches or coppiced trees. In traditional practice, primarily the bark, buds, and young leaves are used; buds are incorporated into syrups and tinctures, while the bark is prepared as decoctions. Leaves have also been applied in the treatment of dental and bone conditions, and the twigs have been used for their depurative (purifying) properties.

Common Commercial and Dosage Forms

Common preparations available on the supplement market include:

Liquid tinctures / fluid extracts — alcohol-based, using dried bark as raw material
Glycerites — alcohol-free preparations using vegetable glycerin as solvent
Dried bark powder — for decoctions or encapsulation
Poultices — bark applied topically for wound and skin conditions
Bark tea (decoction) — prepared by simmering dried bark in water

Tea can be made from the bark of white poplar; it is used for its anti-inflammatory and analgesic properties and has a mild, slightly bitter taste. The bark can also be used in tinctures and poultices for pain relief and to reduce fever.

2. Traditional and Historical Use

Ancient and Classical Traditions

White poplar has been documented since at least the Greek physician Dioscorides (1st century CE), who noted its use for joint pain and respiratory ailments. In Greek mythology, the white poplar was said to be consecrated to Hercules following his defeat of Cacus; in his triumph he crowned himself with the branches of the tree. For this reason, in ancient Greco-Roman mythology, the white poplar became a symbol of a peaceful afterlife, used to honor the memory of the dead.

Chinese healers used poplar tree (Populus alba L.) barks for centuries to treat rheumatic fever, colds, haemorrhages, and goitre, and as a general antiseptic for wounds and abscesses.

European Herbal Tradition

The white poplar has historically been used in European medicine, particularly its bark, which has astringent, antiseptic, and anti-inflammatory properties. Taken internally, it was used to treat a range of complaints ranging from rheumatism and digestive problems to lower back pain and gout. Externally, the bark was made into a poultice to treat infected wounds, haemorrhoids, and chilblains.

The stem bark is described in traditional herbalism as anodyne, anti-inflammatory, antiseptic, astringent, diuretic, and tonic. The bark contains salicylates — the class of compounds from which aspirin is derived — and has been used internally in the treatment of rheumatism, arthritis, gout, lower back pain, urinary complaints, digestive and liver disorders, debility, anorexia, fevers, and menstrual cramps.

The white poplar was first introduced to North America in 1748 and has a long history of cultivation.

Ayurvedic and South Asian Traditions

Populus alba, known as white poplar or silver poplar, is a deciduous tree notable for its silvery leaf undersides and smooth bark. It has a history in Ayurveda for easing coughs, soothing skin irritations, and balancing excess heat. In South Asian traditions, the tree is known as Safeda and its bark has been employed in various preparations for pain and fever.

Traditional Preparation Methods

Decoction: Bark boiled in water, taken internally for inflammatory and febrile conditions.
Poultice: Bark material applied topically to wounds, haemorrhoids, and chilblains.
Tincture: Bark extracted in alcohol for preservation and oral use.
Powder: Inner bark dried and ground; in times of scarcity, the inner bark was dried, ground into a powder, and added to flour for making bread, functioning as a famine food used only when all else failed.

Relation to the History of Salicylate Medicine

The first published report documenting the antipyretic and analgesic properties of salicylate-containing bark appeared in England in 1763, in a presentation to the Royal Society by Reverend Edward Stone. The active component of willow bark was later identified as salicin, which is metabolized to salicylate. In 1832, the French chemist Charles Gerhardt experimented with salicin, generating salicylic acid; and in 1897 Felix Hoffman from the Bayer Company synthesized acetylsalicylic acid — aspirin — which was distributed in tablet and powder form in 1899. White poplar, as a member of the same botanical family (Salicaceae) and a salicin-containing plant, shares this deep historical connection to the origins of analgesic pharmacology.

3. Key Constituents and Active Compounds

Phenolic Glycosides (Salicinoids)

The most pharmacologically significant compound class in Populus alba is the phenolic glycosides, also called salicinoids. Sixteen compounds have been isolated and identified from poplar leaves, including tremuloidin, populin, chaenomeloidin, 4'-O-benzoylsalicin, salicin, tremulacin, poliothrysin benzoate, catechol, benzoic acid, tremulacinol, salicylol, salicortin, and several acetylated and benzoylated derivatives of salicin.

Salicin is the principal salicinoid and the direct precursor to pharmacologically active salicylate. The principal pharmacological effects of salicylate-containing plants arise from their inhibition of COX enzymes. The available evidence suggests that the anti-inflammatory and analgesic properties of traditional NSAIDs are due to inhibition of COX-2, whereas ulcerogenic side effects are associated with inhibition of COX-1.

Populin (salicin-6'-benzoate) is a characteristic glycoside of the genus Populus. Populin (salicin-6′-benzoate) was first identified in the bark of P. balsamifera and has also been identified in the leaves of P. tremula and P. alba.

A comparative study of poplar leaves found that the leaves of P. alba were characterized by the highest content of salicylates among the species examined.

Flavonoids and Phenolic Acids

Using bioassay- and TLC-guided column chromatography, fifteen secondary metabolites were isolated from Populus alba, including a novel plant metabolite, salicyl ether, characterized using UV absorbance, mass spectrometry, and NMR techniques. Among the isolated secondary metabolites investigated from P. alba were aromadendrin, tremuloidin, salicin, isorhamnetin-3-O-β-d-rutinoside, gallocatechin, triandrin, and chrysoeriol-7-O-glucuronide.

Analysis of poplar bud material has revealed predominantly polyphenolic compounds, including phenolic acids and flavonoids, secondary metabolites recognized for their antioxidant properties. For hydroethanolic extracts, P. alba male floral buds yielded a flavonoid content of 2.94 mg/g. HPLC analysis of related poplar species shows that flavonoids in bud extracts are dominated by chrysin, pinocembrin, and galangin, while phenolic acids commonly found in poplar buds include caffeic and p-coumaric acids.

Other Phytochemicals

Main constituents documented in white poplar bark and plant material include caffeic, gallic, and malic acids; salicin (also described as a salicylate pain-reliever); and nigracin, a glycoside. The leaves have been reported to be rich in Vitamin C. The plant product has been described to contain phenolic compounds, terpenoids, flavones, flavanones, and more than 48 phytocompounds in essential oils (as described for closely related species in the genus).

4. Mechanisms of Action

Salicylate-Mediated Anti-inflammatory and Analgesic Action

The primary pharmacological mechanism attributed to white poplar bark extracts is mediated through their salicylate content. Contemporary pharmacological studies reveal that salicin and its metabolites exert multiple biological actions, including suppression of pro-inflammatory cytokines, modulation of nuclear factor kappa B (NF-κB) signaling, and inhibition of cyclooxygenase (COX) enzymes. Owing to these pleiotropic mechanisms, salicin and related phytochemicals have particular therapeutic value in managing chronic inflammatory disorders in which immune dysregulation and oxidative stress play central roles.

The first salicylate targets identified in humans were the cyclooxygenases COX-1 and COX-2. These enzymes convert arachidonic acid — the major plasma membrane fatty acid in animals — into prostaglandins, which have hormone-like activities that induce pain, inflammation, swelling, and fever. These are the same symptoms that are relieved by ingestion of salicylate-rich medicinal plants.

NF-κB Pathway Modulation

Evidence from related Populus species illustrates the inflammatory signaling pathways that may be relevant to white poplar. Studies have demonstrated that poplar bud extract has anti-inflammatory effects, inhibiting the secretion of specific inflammatory cytokines IL-6, IL-10, MCP-1, and TNF-α, and blocking the activation of nuclear factor (NF)-κB. Additionally, extracts from related poplar species inhibit the phosphorylation of NF-κB and IκBα, blunting LPS-triggered nuclear translocation of NF-κB p65; in MAPK signaling, such extracts effectively decrease the phosphorylation of p38 and c-Jun N-terminal protein kinase (JNK), but not of ERK1/2.

Antioxidant Mechanisms

Flavonoids are essential compounds produced through the phenylpropanoid pathway. Flavonoids have antioxidative, anti-inflammatory, anti-mutagenic, and anti-carcinogenic properties related to regulating necessary cellular enzyme functions. Flavonoids inhibit enzymes such as aldose reductase, xanthine oxidase, phosphodiesterase, Ca2+ ATPase, lipoxygenase, and cyclooxygenase (COX). Flavonoids also prevent damage caused by free radicals, including direct scavenging, and are themselves oxidized by radicals into more stable, less reactive species.

Antibacterial Mechanisms

The effective substances from the genus Populus are identified in conventional medication for diverse biological activities involving antioxidant, antiseptic, antiviral, antifungal, and antitumoral properties. In terms of antibacterial activity specifically for P. alba, crude extracts of P. alba showed moderate in vitro activity against Gram-positive bacteria including S. aureus ATCC 29213, S. aureus ATCC 6538, MRSA, E. freundii, and L. innocua. Low activity was recorded against Gram-negative bacteria such as E. coli and P. aeruginosa.

5. Scientific Evidence by Area of Use

5.1 Anti-inflammatory and Analgesic Effects

Preclinical and in vitro evidence: P. alba extracts and their sub-fractions exhibited promising antioxidant activities in vitro in DPPH and FRAP assays, and extracts of P. alba leaves and shoots demonstrated substantial antioxidant activities in vivo in the multicellular model organism Caenorhabditis elegans. Evidence from related poplar species further supports the anti-inflammatory activity of the genus. Anti-inflammatory effects of tremulacin, a salicin-related substance isolated from Populus tomentosa leaves, have been documented in Phytomedicine (1994).

Human/clinical evidence: No human clinical trials specifically evaluating Populus alba bark or extract as an isolated intervention for pain or inflammation were identified in the peer-reviewed literature accessible for this article. The anti-inflammatory and analgesic claims associated with white poplar are primarily based on: (1) its documented salicylate content and the well-established pharmacology of salicylates; and (2) extrapolation from clinical studies on closely related salicylate-rich plants such as white willow bark (Salix alba). A significant limitation is the lack of large-scale, modern clinical trials specifically on Populus species for pain relief. Most current knowledge is extrapolated from studies on white willow bark or the known pharmacology of salicylic acid. More specific research is needed to establish definitive efficacy and dosing guidelines.

Evidence strength: Preliminary and indirect. The analgesic and anti-inflammatory rationale is mechanistically plausible given the phytochemical profile, but direct clinical evidence in humans using P. alba specifically is absent from the published literature.

5.2 Antioxidant Effects

In vitro and model-organism evidence: A comprehensive study aimed at identifying secondary metabolites in the leaves of Populus alba, Populus × candicans, and Populus nigra determined total salicylate, flavonoid, and phenolic compound contents and assessed antioxidant potential using DPPH, ABTS, and FRAP assays, as well as 2D-TLC bioautography including xanthine oxidase inhibition tests. Among the 80 identified compounds, 13 were shown for the first time in the genus Populus. Numerous salicylic compounds were present in the leaves of P. alba. All analyzed leaves were a rich source of phenolic compounds. The highest content of salicylates was found in the leaves of P. alba. All examined poplar leaves demonstrated antioxidant potential in all assays used.

Polyphenolic content in poplar buds (across three species including P. alba) ranged from 19.26 to 33.37 mg GAE/g DW, and flavonoid content from 2.15 to 4.45 mg RE/g DW. All three species demonstrated notable antioxidant capacity.

Evidence strength: Moderate for in vitro and model-organism activity. No human trials on antioxidant outcomes exist for this plant. The relevance of in vitro antioxidant assay results to in vivo human health outcomes is inherently uncertain.

5.3 Antimicrobial Effects

In vitro evidence: The efficacy of ethanolic extracts of P. alba leaves against various microorganisms has been established. A study proposed that white poplar leaf extract (WPE) might provide a promising alternative to traditional antibiotics for treating Aeromonas veronii infection; WPE showed in vitro antibacterial activity with an inhibition zone of 22 ± 0.45 mm and a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 60 µg/mL against A. veronii.

In a separate study on bud extracts from Algerian material, crude extracts of P. alba showed moderate in vitro activity against Gram-positive bacteria and low activity against Gram-negative species.

Since ancient times, poplar bud decoctions and extracts were used for wound healing, alleviation of dermatitis symptoms, treatment of rheumatism, and infection. Studies of antimicrobial activity have shown that extracts from related poplar species have a growth inhibitory effect against Staphylococcus aureus and Candida albicans.

Evidence strength: Preliminary (in vitro only). No human clinical trials on antimicrobial applications of P. alba were identified.

5.4 Wound Healing

Wound healing activity of the essential oils of Rosmarinus officinalis and Populus alba has been investigated in a burn wound model in rats. This represents animal-model evidence. In traditional external use, the bark was applied to treat chilblains, haemorrhoids, infected wounds, and sprains. The wound healing evidence for P. alba specifically is limited to animal and in vitro models; no human trials were identified.

5.5 Aquaculture / Immunostimulant Effects (Animal Studies)

An in vivo study used a factorial (2 × 2) design to investigate the therapeutic effects of white poplar leaf extract (WPE) on the antioxidant/immune status and blood biochemical parameters of Nile tilapia (Oreochromis niloticus) challenged with Aeromonas veronii. One hundred sixty fish (33 ± 1.5 g) were assigned to four experimental groups, each with four replicates, for 10 days. This study provides data in a fish model and has no direct relevance to human supplementation use.

5.6 Traditional Indications with No Current Clinical Evidence

Traditional uses for which no verifiable modern human clinical evidence was identified include:

Urinary complaints and prostate inflammation — poplar leaves are a herbal remedy traditionally used for the treatment of rheumatic diseases and prostate inflammation.
Digestive and liver disorders
Menstrual cramping
Gout
Respiratory ailments including bronchitis

For all of the above conditions, the evidence base is traditional or ethnomedical only; no controlled clinical trials specific to P. alba have been identified in the peer-reviewed literature.

6. Body Systems and Health Areas

Based on traditional use and phytochemical properties documented in the literature, Populus alba is associated with the following body systems:

Musculoskeletal system — historically used for arthritis, rheumatism, gout, and lower back pain
Immune and inflammatory system — NF-κB and COX-mediated anti-inflammatory activity demonstrated in preclinical studies
Skin and integument — traditional topical use for wounds, haemorrhoids, and chilblains; some animal-model wound healing evidence
Urinary tract — traditional use for urinary complaints
Reproductive system — historical use for menstrual cramping
Gastrointestinal and hepatic systems — traditional use for digestive and liver disorders
Respiratory system — traditional use for coughs and bronchitis; Ayurvedic use for respiratory conditions
Antioxidant/cellular defense — well-characterized in vitro antioxidant properties across multiple assay systems

7. Dosage Forms and Reported Dosages

No standardized human clinical dosage ranges have been established by regulatory or pharmacopoeial bodies for Populus alba specifically. The following dosages are those reported in available sources:

Liquid tincture (1:3 dry plant material to menstruum ratio): 20–30 drops taken three times per day, or as directed by a practitioner. The tincture may be placed in a glass of water, tea, or juice and the entire contents consumed.
Aquaculture (animal research): White poplar leaf extract with an in vitro antibacterial MIC and MBC of 60 µg/mL against A. veronii. (This is a non-human research dosage.)

No peer-reviewed human clinical trial specifying a dosage for P. alba bark or leaf extract was identified. Published dosage guidance in supplement contexts remains practitioner- or manufacturer-dependent and is not validated by clinical trials.

8. Safety Considerations and Potential Interactions

Salicylate Sensitivity and Allergy

The most significant safety consideration for white poplar is its salicylate content. Salicylates in these trees can cause allergic reactions in people who are sensitive to aspirin. Anyone with asthma, nasal polyps, or known salicylate sensitivity should avoid these and any other significant sources of salicylates.

Platelet Aggregation and Anticoagulant Interactions

The salicylates found in poplar trees do not have any clinically significant effect on platelet aggregation. Thus, there is no established reason to avoid combining them with aspirin or anticoagulant medications out of concern for increased risk of bleeding. They also cannot be substituted for aspirin in reducing the risk of atherosclerotic complications, as far as is known. However, pharmacologically cautious practitioners may still advise monitoring when combining any salicylate-containing botanical with anticoagulants or antiplatelet medications.

Gastrointestinal Tolerability

Willow, aspen, and birch — and by extension other members of the Salicaceae family — have not been demonstrated to cause peptic ulcer or gastrointestinal bleeding at usual therapeutic doses. Gastrointestinal upset may occur in sensitive individuals, and there is potential for allergic reactions, especially in people allergic to aspirin or salicylates.

Reye's Syndrome Risk in Children

There is no information available about natural salicylates and Reye's syndrome specifically, but for the sake of greatest safety, salicylate-containing plants should be avoided in children with influenza until more information is available.

Pregnancy and Breastfeeding

White poplar preparations are not recommended during pregnancy or breastfeeding, and should be avoided by individuals with asthma, salicylate sensitivity, or gastrointestinal ulcers.

Drug Interactions

Salicylate-containing plants from the genus Populus may interact with certain pharmaceuticals, potentially altering their effectiveness or increasing the risk of side effects. Their anti-inflammatory and analgesic properties may enhance or interfere with medications such as NSAIDs and anticoagulants. They may also interact additively with other salicylate-containing supplements such as willow bark.

General Toxicity

Toxicity of poplar preparations is reported to be low when used in recommended dosages. No formal toxicological studies specifically on P. alba bark extracts in humans were identified in the published literature.

Summary of Evidence Quality

Populus alba possesses a well-characterized phytochemical profile dominated by salicylate-class phenolic glycosides (including salicin, populin, tremuloidin, and tremulacin) together with diverse flavonoids and phenolic acids. The mechanistic rationale for anti-inflammatory, analgesic, and antioxidant properties is scientifically sound and based on characterized active compounds. However, as of the time of writing, no human clinical trials specifically using P. alba as an isolated intervention have been published. The evidence base consists primarily of: (1) well-documented traditional use across Chinese, Greco-Roman, European, and Ayurvedic systems; (2) in vitro phytochemical and bioassay data; and (3) extrapolation from the pharmacology of salicylates and from clinical research on related Salicaceae species. The overall evidence for efficacy in humans must therefore be characterized as preliminary and indirect.

References

Health Conditions

Health conditions that White poplar may help support.

No conditions available.

Body Systems

Body systems that White poplar may help support.

No body systems available.